1. Field of the Invention
The present invention relates to a method for supporting a Peer-to-Peer (P2P) communication in a wireless communication. More particularly, the present invention relates to a scheme for, even if a Mobile Station (MS) is in a sleep mode or inactive mode, providing a P2P service immediately when there is a request for a P2P communication.
2. Description of the Related Art
In the conventional art, MSs use a different frequency band to perform a conventional P2P communication than a frequency band allocated to a wireless communication system. Also, MSs use a separate RF transmitting/receiving apparatus to process a different frequency band signal. For instance, an Infrared Data Association (IrDA), a Bluetooth communication and the like are used in a P2P communication. However, if the P2P communication and wireless communication use the same frequency band, bandwidth efficiency can be improved by flexibly adjusting each transmission band if an interference problem is solved by using an efficient resource management scheme. For this purpose, a WINNER system project is planned for use in Europe.
FIG. 1 is a diagram illustrating a conventional state transition of an MS in a wireless communication system.
Referring to FIG. 1, a transition state of an MS includes a first active state 100, an inactive state 102, and a P2P active state 108.
The first active state 100 is a state where an MS is in communication with a different MS through a Base Station (BS). The inactive state 102 is a state where the MS is on standby with no communication. The P2P active state 108 is a state where the MS is in a direct P2P communication with a different MS.
If there is no connection request from the BS for a preset period of time, the MS transits to the inactive state 102 from the first active state 100 to reduce power consumption, thus receiving no data for a preset period of time. The MS transits to the inactive state 102 upon wireless communication termination 104.
In the inactive state 102, the MS performs a short communication to identify whether there is data to be received from the BS, whether there is a need for handover, etc. during a preset period of time. Then, the MS returns to a reception stop state upon the lapse of the preset period of time. If there is a connection request 106 from the BS, the MS transits to the first active state 100 from the inactive state 102.
However, if the P2P communication and the wireless communication use the same frequency band, the P2P communication is carried out in a separate independent mode from the wireless communication and therefore, in the inactive state 102, the MS cannot process a P2P connection request message if there is a connection request from an MS that desires the P2P communication. Thus, a user must perform a manual transition 110 to the P2P active state for the P2P communication. Therefore, there is a disadvantage that a prompt P2P connection is not established.
As described above, because the existing P2P communication uses a different frequency band from the wireless communication, a separate RF module is required and also, a connection method is designed and managed such that the P2P communication is operated in a separate mode from the wireless communication. When the P2P communication and the wireless communication use the same frequency band, an RF module uses a single module as well. However, this may cause a problem in that the P2P communication cannot be managed in a separate mode. In other words, because an MS in an inactive mode can perform a data exchange only with a BS during a preset period of time, there is a problem that the MS cannot process P2P connection request messages received from neighboring MSs that desire the P2P communication, thus causing a difficulty in establishing a P2P communication connection.
Therefore, a need exists for an improved method for supporting a peer-to-peer communication in a wireless communication.